AU2007343217B2

AU2007343217B2 - Heat exchanger with plates

Info

Publication number: AU2007343217B2
Application number: AU2007343217A
Authority: AU
Inventors: Olivier Noel-Baron; Christophe Wibaut
Original assignee: Alfa Laval Vicarb SAS
Current assignee: Alfa Laval Vicarb SAS
Priority date: 2006-12-21
Filing date: 2007-12-20
Publication date: 2011-02-17
Anticipated expiration: 2027-12-20
Also published as: JP2010513839A; ES2842048T3; PL2097705T3; WO2008084174A2; FR2910607B1; RU2439457C2; BRPI0720444A2; EP2097705A2; CN101573580A; JP5430404B2; CN101573580B; CA2673014C; FR2910607A1; US8544529B2; US20100044021A1; WO2008084174A3; CA2673014A1; RU2009128028A; AU2007343217A1; DK2097705T3

Description

HEAT EXCHANGER WITH PLATES Technical Field The invention relates to the field of heat exchangers 5 with plates between which two fluids brought to different temperatures flow and one of which receives/drains the heat energy of the other. The invention is more particularly targeted at exchangers with large-sized plates, the frame of which has 10 on the inside a guide rail for guiding the plates in parallel inside the frame before the plates are tightened to each other to provide the seal between the two circuits. Prior Art 15 Generally speaking, in order to provide the seal between the different fluid circuits, a peripheral seal is placed on each of the plates of the exchanger. Such plates fitted with peripheral seals are described in particular in the document GB-1 592 069. 20 However, when the plates are very large in size, a displacement may occur between each of the plates when they are inserted inside the frame and then when the plates are tightened against each other. Said displacement may be caused in particular by using a seal which is 25 pointed in shape and is also known by the term "ROOF TOP". Indeed, when a plate comes into contact with the tip of the seal of the adjacent plate, it is then positioned substantially crosswise and swings around the edge defined by the tip of the seal. This phenomenon is 30 especially marked when the plates have a single guiding 25335091 (GHMatters) 12/01111 -2 cut to facilitate the installation of the plates inside the frame. It would be advantageous if the present invention would eliminate the displacement which may occur between 5 the different plates of a heat exchanger when the plates are positioned in the frame and then when the plates are tightened against each other. Moveover, this objective is met and without detriment to the sealing function fulfilling by the peripheral seal. 10 Description of the Invention The invention therefore relates to a heat exchanger comprising a set of plates defining between them circuits for a fluid flowing alternatively via seals mounted between each pair of two adjacent plates. Each plate is includes at least one guiding cut formed at least at one of the ends thereof and which allows each plate to be guided inside a frame. According to the invention, the heat exchanger is characterised in that it also includes between each pair 20 of two adjacent plates, and in proximity to the guiding cut, at least one strut to be compressed and in contact with the two adjacent plates, each strut having before compression a thickness at least equal to that of the seal. 25 In other, words, when the plates of the exchanger are positioned inside the frame, they may be oriented in parallel relative to each other while coming into contact with the strut positioned on the adjacent plate. Furthermore, before the plates are tightened against each 30 other, the seal is not acted upon and consequently it does not some into contact with the adjacent plate. Thus, when plate tightening commences, the plates may 25335091 (GHMatters) 12/01/11 -3 all be arranged in parallel relative to each other and the heat exchanger may be arranged such that no displacement can occur, even when the seal is pressurised since the strut positioned in proximity to the guiding cut prevents s any swinging of one plate relative to the other. To advantage, each strut may be inserted into a groove formed in one of the plates with which it comes into contact. Indeed, like the seal, the strut may be positioned, 10 or even bonded, inside a groove thereby preventing the strut from sliding in particular during tightening. These grooves may generally be made by means of a press and a stamp during the plate die stamping operation so as to generate a plurality of corrugations 15 thereby increasing the surface of the heat exchange between the fluids inside the exchanger. In practice, each strut may be substantially in the shape of a rectangular parallelepiped. As such, it comprises two parallel faces, and it is of constant cross 20 section compatible with a manufacturing process such as extrusion or moulding. According to one particular embodiment, each strut may offer greater compressibility than the seal. Therefore, when the plates are tightened against each 25 other, the strut, which has a thickness greater than that of the strut, is capable of being compressed without hindering the subsequent compression of the seal. 25335091 (GHMatters) 12/01/11 Furthermore, such a strut may be made in different ways and be secured or not secured to the seal. According to a first alternative, each strut may be an excrescence of the seal. The seal and the strut thus 5 form a monolithic unit which can be made in a single operation, in particular via a moulding process. To advantage, the heat exchanger may comprise a link portion between each seal and each strut. This configuration allows the strut to be placed in 10 proximity to the guiding cut, without however changing the position of the seal on the plate. The only function of this link portion is to make it easier to manufacture the exchanger by avoiding an increase in the number of parts in its constitution and to position the strut on the 15 plate. This link portion has a thickness which is less than that of the seal, and consequently less than that of the strut as well. According to a second alternative, each strut may be disconnected from the seal. As such, it is possible 20 to arrange each of the elements on a plate independently. Such an alternative therefore means that the link portion can be eliminated and the existing seals used in conventional already manufactured heat exchangers. Different seal and strut embodiments are conceivable 25 and in particular they may be made out of materials that are or are not different. Thus, according to a first embodiment, the struts and the seals may be made out of a single material. They may thus for example be moulded in the same mould and 30 manufactured simultaneously. 25335091 (GHMatters) 12101/11 -5 According to a second embodiment, the struts and seals may be made out of two different materials. As such, it is in particular possible to adapt the compressibility of the struts so as not to change locally 5 the compressibility of the seal. Brief Description of the Figures The way the invention is embodied, and the resulting advantages, will become clearer from the following embodiment description, given by way of 10 information but non-restrictively, supported by the figures wherein: - figure 1 is a partial cross-section view of a heat exchanger in accordance with an embodiment of the invention; 15 - figure 2 is a partial front view of an exchanger plate; - figures 3 and 4 are transverse cross section views of different forms of the strut at the interstice between two plates before they are tightened against each other. 20 - figures 3 and 4 are transverse cross-section views of different forms of the strut at the interstice between two plates before they are tightened against each other. Description of Embodiment of the Invention 25 As already mentioned, the invention relates to a heat exchanger (1) as shown in figure 1. This type of exchanger with plates (10) thus includes two fluid circuits (2,3) wherein two fluids flow in order to exchange their heat energy. 2533509_1 (GHMatters) 12/01/11 -6 As shown, these circuits (2, 3) are defined by a seal (4) defining the periphery of the exchange area on each plate. The plates (10) are positioned inside a frame (6) and are guided in this frame via a guiding cut (5) s engaging with a rail mounted on the frame (6). Struts (7) then allow each plate (10) to be positioned equidistant from one another and in parallel in proximity to this guide rail. The struts (7) are thus used to ensure the parallel positioning of the plates relative to each other 10 before the tightening operation to compress the seal (4). In the alternative shown, the struts (7) may form an excrescence of the seal (4) . This embodiment facilitates operations to assemble and manufacture such an exchanger (1). 15 As shown by the alternative in figure 2, the struts (17) may also be disconnected from the seal (4). It is thus possible to make heat exchangers in accordance with an embodiment of the invention by using a conventional already produced seal. 20 As shown in figure 3, the strut (7) is in this case an excrescence of the seal (4) and is connected to it by means of a link portion (9) . Furthermore, the thickness (E) of the strut (7) is greater than the thickness (e) of the seal (4) . In this way, an upper face (27) of the 25 strut (7) is first to come into contact with the upper plate (11) when the plates (10,11) are positioned opposite one another in the frame (6). By way of example, a seal may be used with a thickness e of 6mm combined with a strut with a thickness 30 E of 6.2mm. 25335091 (GHMatters) 12/01/11 -7 Furthermore, a lower face (37) of the strut (7) comes to engage with a groove (8) to ensure that the strut (7) can be easily installed on and secured to the plate (10). Indeed, the strut (7) must be very accurately 5 positioned on the plate (10) so as to engage with a plane surface on the back of the plate (11) opposite. The upper (27) and lower (37) faces are, in the alternative shown, substantially plane so as to form a strut (7) substantially in the shape of a 10 rectangular parallelepiped. According to another alternative, and as shown in figure 4, the upper (27) and lower (37) faces may also form a warped concave-shaped surface before compression. In this case, when tightening, the contact between the is strut (7) and the adjacent plate (11) is linear before becoming by surface area. Such a linear contact in proximity to the guide rail does however make it possible to guarantee that the plates can be positioned in parallel relative to each other. 20 It becomes clear from what has been said above that an exchanger with plates in accordance with embodiments of the invention has manifold advantages, and in particular: - it allows the plates to be positioned in 25 parallel relative to each other, and perpendicular relative to the direction of thrust exerted when tightening the plates one against the other. - it allows in particular a single guide rail to be 30 used, thereby facilitating the installation of very large-sized plates. 25335091 (GHMatters) 12/01/11 -8 It is to be understood that, if any prior art publication is referred to herein, such reference does not constitute an admission that the publication forms a part of the common general knowledge in the art, in Australia 5 or any other country. 25335091 (GHMatters) 12/01/11

Claims

1. Heat exchanger comprising a set of plates defining between them circuits for a fluid flowing alternately via seals mounted between each pair of two adjacent 5 plates, each plate including at least one guiding cut formed at least at one of the ends thereof for guiding each plate inside a frame characterized in that it also includes between each pair of two adjacent plates, and in proximity to the guiding cut, at least one strut to be 10 compressed and in contact with the two adjacent plates, each strut having, before compression, a thickness at least equal to that of the seal.

2. Heat exchanger as claimed in claim 1, characterized in that each strut is inserted into a groove formed in one 15 of the plates with which it comes into contact.

3. Heat exchanger as claimed in claim 1, characterized in that each strut is substantially in the shape of a rectangular parallelepiped.

4. Heat exchanger as claimed in claim 1, characterized 20 in that each strut has greater compressibility than the seal (4).

5. Heat exchanger as claimed in claim 1, characterized in that each strut is an excrescence of the seal.

6. Heat exchanger as claimed in claim 5, characterized 25 in that it comprises a link portion between each seal and each strut.

7. Heat exchanger as claimed in claim 1, characterized in that each strut is disconnected from the seal. 25335091 (GHMatters) 12/01/11 - 10

8. Heat exchanger as claimed in one of claims 5 or 7, characterized in that the struts and the seals are made out of a single material.

9. Heat exchanger as claimed in one of claims 5 or 7, s characterized in that the struts and the seals are made out of two different materials.

10. Heat exchange substantially as herein described with reference to one or more of the drawings. 10 25335091 (GHMatters) 12101/11